Very bad experiance withthis....Spirit is VERY strict about it and flight attendants on this particular flight from Florida to Detroit were RUDE AS HECK!!! Not to say all sre rude...but these 3 were vicious. And yes they throughly examined our bags and demanded Bella be tightly under the seat even though she was crying and scared. I was miserable the whole flight as was Bella....she stressed and panted the whole time. They also examined her health cert. and they are only good for 2 weeks, we were in FLorida for 2 weeks 3 days so had to re-cert in florida.....it was crazy. Just my experiance dont mean to seem negative but the meanies are out there!